Nec Corporation

Laserfront Technologies, Inc.

Yukio Kyusho

Yukio Morishige

Motohiro Arai

Yoichi Yoshino

A method for repairing a pattern by using a laser and a laser-based pattern repair apparatus are provided which are capable of reducing splashes, rolling-up, and damage to a glass substrate to a minimum in pattern defects repairing processing by removing a thin metal layer such as a chromium layer. A part of a string of pulses obtained by slicing, using an optical shutter, pulses from laser light having a pulse width of 10 ps to 300 ps emitted from a Q-switched mode-locked pulse laser is used to produce multi-pulses which are divided into two portions in terms of time base correction using an optical delaying unit.

Method and apparatus for performing pattern defect repair using Q-switched mode-locked pulse laser

The diameter of the spot of the light output from a laser diode is reduced through a coupled optical system so as to be smaller than the incidence aperture of a tapered total reflection rod. The light output from the coupling optics is focused into the incidence aperture of the total reflection rod. The total reflection rod is equipped with a smaller emission aperture than the diameter of the incidence aperture and further reduces the spot of the focused light. That is, the light passing through the total reflection rod is reduced to a smaller diameter while being totally reflected internally. A laser medium is in optical contact with the emission aperture of the total reflection rod and is pumped by the light which is output from the total reflection rod.

Solid-state laser device which is pumped by light output from laser diode

An atmospheric laser which is transversely excited includes main and preliminary discharge electrodes. Life of laser gas used to promote ionization between the main discharge electrodes is lengthened by providing a sufficient number of preliminary discharge electrodes, at a distance sufficiently close to the main discharge electrodes to promote preliminary ionization in a preliminary discharge space, prior to discharge in the main discharge space. According to preferred embodiments of the invention, one of the rare gases such as He is provided in the preliminary discharge space, and a mixture of CO.sub.2, N.sub.2, and He is provided in the main discharge. In order to enable the preliminary discharge electrodes to be closer to the main discharge electrodes, air may be used in place of one of the rare gases in the preliminary discharge space, so that the overall apparatus may be made yet smaller.

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Tokyo, Japan

Yukio Kyusho